Hemianopsia
Condition
(Hemianopia; Hemiopia; Bitemporal Hemianopsia; Homonymous Hemianopsia; Left Homonymous Hemianopsia; Right Homonymous Hemianopsia; Superior Hemianopsia; Inferior Hemianopsia)
Definition
Hemianopsia is the loss of half of the visual field. A person with hemianopsia only sees a portion of the visual field from each eye. It is classified by where the missing visual field is located:
- Outer half of each visual field (bitemporal)
- The same half of each visual field (homonymous)
- Right half of each visual field (right homonymous)
- Left half of each visual field (left homonymous)
- Upper half of each visual field (superior)
- Lower half of each visual field (inferior)
Causes
Hemianopsia is caused by health problems that affect the brain or optic nerves. Common ones are:
Less common causes are:
- Infections
- Seizures
- Migraines
- Exposure to toxins
- Brain disorders that get worse over time
- Nonketotic hyperglycemia
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Risk Factors
The risk of hemianopsia is higher in people who have a condition that affects the brain. A problem with the optic nerve may also raise the risk, but this is not as common.
Symptoms
Vision loss can be mild to severe. A person with hemianopsia may have:
- Bumping into objects
- Problems reading
- Problems driving, such as changing lanes when there is an oncoming car or sideswiping objects
- Seeing lights or shapes that are not there
Diagnosis
The doctor will ask about symptoms and health history. A physical exam will be done. A doctor who treats the eyes or one who treats problems of the brain may need to be seen.
The doctor will test a person's field of vision. This can be done with a visual field test that makes a map of a person's field of vision.
Images may be taken of structures in the brain. This can be done with an MRI scan.
Treatment
Any underlying causes of hemianopsia will need to be treated. This may help some people see better.
For others, the goal of treatment will be to manage vision loss. Choices are:
- Visual aids, such as mirrors, telescopes, and prisms that are attached to eyeglasses
- Reading strategies, such as using a ruler to mark the start and end of text
- Lifestyle changes, such as turning the head and eyes to view things outside of one's field of vision
Prevention
The risk of hemianopsia may be lowered by managing health problems that could lead to a stroke.
American Academy of Ophthalmology
Lighthouse Guild
CANADIAN RESOURCES:
Canadian Ophthalmological Society
Canadian Stroke Network
American Academy of Ophthalmology
Lighthouse Guild
CANADIAN RESOURCES:
Canadian Ophthalmological Society
Canadian Stroke Network
References
- Brain abscess. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/brain-abscess.
- Homonymous hemianopia. North American Neuro-Ophthalmology Society website. Available at: http://www.nanosweb.org/files/public/Homonymous_hemianopia.pdf.
- Ophthalmologic manifestations of migraines. EyeWiki—American Academy of Ophthalmology website. Available at: https://eyewiki.aao.org/Ophthalmologic_Manifestations_of_Migraines.
- Tajfirouz, D., Chen J.J., et al. Clinical reasoning: an 80-year-old woman with homonymous hemianopsia. Neurology, 2022; 99 (16): 713-717.
Contributors
- Rimas Lukas, MD
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